truck dies when i put it in gear on 1990 GMC 1500 Pickup

first off its a 1982 gmc sierra c1500 it has a carbureted 350 with a manual choke. I just rebuilt the 750 cfm carb and all the adjustments are set back to factory. But when i start the truck it runs fine but whenever i put it in gear and mash the gas it dies. If anyone can help i would greatly appreciete it.
Thanks,
Bud